/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xerces.internal.impl.xs;

import com.sun.org.apache.xerces.internal.impl.xs.util.XSGrammarPool;
import com.sun.org.apache.xerces.internal.xni.grammars.Grammar;
import com.sun.org.apache.xerces.internal.xni.grammars.XMLGrammarDescription;
import com.sun.org.apache.xerces.internal.xni.grammars.XSGrammar;
import com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource;
import com.sun.org.apache.xerces.internal.xs.LSInputList;
import com.sun.org.apache.xerces.internal.xs.StringList;
import com.sun.org.apache.xerces.internal.xs.XSConstants;
import com.sun.org.apache.xerces.internal.xs.XSLoader;
import com.sun.org.apache.xerces.internal.xs.XSModel;
import com.sun.org.apache.xerces.internal.xs.XSNamedMap;
import com.sun.org.apache.xerces.internal.xs.XSObjectList;
import com.sun.org.apache.xerces.internal.xs.XSTypeDefinition;
import org.w3c.dom.DOMConfiguration;
import org.w3c.dom.DOMException;
import org.w3c.dom.DOMStringList;
import org.w3c.dom.ls.LSInput;

/**
 * <p>An implementation of XSLoader which wraps XMLSchemaLoader.</p>
 *
 * @author Michael Glavassevich, IBM
 * @version $Id: XSLoaderImpl.java,v 1.7 2010-11-01 04:39:55 joehw Exp $
 * @xerces.internal
 */
public final class XSLoaderImpl implements XSLoader, DOMConfiguration {

  /**
   * Grammar pool. Need this to prevent us from
   * getting two grammars from the same namespace.
   */
  private final XSGrammarPool fGrammarPool = new XSGrammarMerger();

  /**
   * Schema loader.
   **/
  private final XMLSchemaLoader fSchemaLoader = new XMLSchemaLoader();

  /**
   * No-args constructor.
   */
  public XSLoaderImpl() {
    fSchemaLoader.setProperty(XMLSchemaLoader.XMLGRAMMAR_POOL, fGrammarPool);
  }

  /**
   * The configuration of a document. It maintains a table of recognized
   * parameters. Using the configuration, it is possible to change the
   * behavior of the load methods. The configuration may support the
   * setting of and the retrieval of the following non-boolean parameters
   * defined on the <code>DOMConfiguration</code> interface:
   * <code>error-handler</code> (<code>DOMErrorHandler</code>) and
   * <code>resource-resolver</code> (<code>LSResourceResolver</code>).
   * <br> The following list of boolean parameters is defined:
   * <dl>
   * <dt>
   * <code>"validate"</code></dt>
   * <dd>
   * <dl>
   * <dt><code>true</code></dt>
   * <dd>[required] (default) Validate an XML
   * Schema during loading. If validation errors are found, the error
   * handler is notified. </dd>
   * <dt><code>false</code></dt>
   * <dd>[optional] Do not
   * report errors during the loading of an XML Schema document. </dd>
   * </dl></dd>
   * </dl>
   */
  public DOMConfiguration getConfig() {
    return this;
  }

  /**
   * Parses the content of XML Schema documents specified as the list of URI
   * references. If the URI contains a fragment identifier, the behavior
   * is not defined by this specification.
   *
   * @param uriList The list of URI locations.
   * @return An XSModel representing the schema documents.
   */
  public XSModel loadURIList(StringList uriList) {
    int length = uriList.getLength();
    try {
      fGrammarPool.clear();
      for (int i = 0; i < length; ++i) {
        fSchemaLoader.loadGrammar(new XMLInputSource(null, uriList.item(i), null));
      }
      return fGrammarPool.toXSModel();
    } catch (Exception e) {
      fSchemaLoader.reportDOMFatalError(e);
      return null;
    }
  }

  /**
   * Parses the content of XML Schema documents specified as a list of
   * <code>LSInput</code>s.
   *
   * @param is The list of <code>LSInput</code>s from which the XML Schema documents are to be
   * read.
   * @return An XSModel representing the schema documents.
   */
  public XSModel loadInputList(LSInputList is) {
    final int length = is.getLength();
    try {
      fGrammarPool.clear();
      for (int i = 0; i < length; ++i) {
        fSchemaLoader.loadGrammar(fSchemaLoader.dom2xmlInputSource(is.item(i)));
      }
      return fGrammarPool.toXSModel();
    } catch (Exception e) {
      fSchemaLoader.reportDOMFatalError(e);
      return null;
    }
  }

  /**
   * Parse an XML Schema document from a location identified by a URI
   * reference. If the URI contains a fragment identifier, the behavior is
   * not defined by this specification.
   *
   * @param uri The location of the XML Schema document to be read.
   * @return An XSModel representing this schema.
   */
  public XSModel loadURI(String uri) {
    try {
      fGrammarPool.clear();
      return ((XSGrammar) fSchemaLoader.loadGrammar(new XMLInputSource(null, uri, null)))
          .toXSModel();
    } catch (Exception e) {
      fSchemaLoader.reportDOMFatalError(e);
      return null;
    }
  }

  /**
   * Parse an XML Schema document from a resource identified by a
   * <code>LSInput</code> .
   *
   * @param is The <code>LSInput</code> from which the source document is to be read.
   * @return An XSModel representing this schema.
   */
  public XSModel load(LSInput is) {
    try {
      fGrammarPool.clear();
      return ((XSGrammar) fSchemaLoader.loadGrammar(fSchemaLoader.dom2xmlInputSource(is)))
          .toXSModel();
    } catch (Exception e) {
      fSchemaLoader.reportDOMFatalError(e);
      return null;
    }
  }

  /* (non-Javadoc)
   * @see com.sun.org.apache.xerces.internal.dom3.DOMConfiguration#setParameter(java.lang.String, java.lang.Object)
   */
  public void setParameter(String name, Object value) throws DOMException {
    fSchemaLoader.setParameter(name, value);
  }

  /* (non-Javadoc)
   * @see com.sun.org.apache.xerces.internal.dom3.DOMConfiguration#getParameter(java.lang.String)
   */
  public Object getParameter(String name) throws DOMException {
    return fSchemaLoader.getParameter(name);
  }

  /* (non-Javadoc)
   * @see com.sun.org.apache.xerces.internal.dom3.DOMConfiguration#canSetParameter(java.lang.String, java.lang.Object)
   */
  public boolean canSetParameter(String name, Object value) {
    return fSchemaLoader.canSetParameter(name, value);
  }

  /* (non-Javadoc)
   * @see com.sun.org.apache.xerces.internal.dom3.DOMConfiguration#getParameterNames()
   */
  public DOMStringList getParameterNames() {
    return fSchemaLoader.getParameterNames();
  }

  /**
   * Grammar pool which merges grammars from the same namespace into one. This eliminates
   * duplicate named components. It doesn't ensure that the grammar is consistent, however
   * this no worse than than the behaviour of XMLSchemaLoader alone when used as an XSLoader.
   */
  private static final class XSGrammarMerger extends XSGrammarPool {

    public XSGrammarMerger() {
    }

    public void putGrammar(Grammar grammar) {
      SchemaGrammar cachedGrammar =
          toSchemaGrammar(super.getGrammar(grammar.getGrammarDescription()));
      if (cachedGrammar != null) {
        SchemaGrammar newGrammar = toSchemaGrammar(grammar);
        if (newGrammar != null) {
          mergeSchemaGrammars(cachedGrammar, newGrammar);
        }
      } else {
        super.putGrammar(grammar);
      }
    }

    private SchemaGrammar toSchemaGrammar(Grammar grammar) {
      return (grammar instanceof SchemaGrammar) ? (SchemaGrammar) grammar : null;
    }

    private void mergeSchemaGrammars(SchemaGrammar cachedGrammar, SchemaGrammar newGrammar) {

      /** Add new top-level element declarations. **/
      XSNamedMap map = newGrammar.getComponents(XSConstants.ELEMENT_DECLARATION);
      int length = map.getLength();
      for (int i = 0; i < length; ++i) {
        XSElementDecl decl = (XSElementDecl) map.item(i);
        if (cachedGrammar.getGlobalElementDecl(decl.getName()) == null) {
          cachedGrammar.addGlobalElementDecl(decl);
        }
      }

      /** Add new top-level attribute declarations. **/
      map = newGrammar.getComponents(XSConstants.ATTRIBUTE_DECLARATION);
      length = map.getLength();
      for (int i = 0; i < length; ++i) {
        XSAttributeDecl decl = (XSAttributeDecl) map.item(i);
        if (cachedGrammar.getGlobalAttributeDecl(decl.getName()) == null) {
          cachedGrammar.addGlobalAttributeDecl(decl);
        }
      }

      /** Add new top-level type definitions. **/
      map = newGrammar.getComponents(XSConstants.TYPE_DEFINITION);
      length = map.getLength();
      for (int i = 0; i < length; ++i) {
        XSTypeDefinition decl = (XSTypeDefinition) map.item(i);
        if (cachedGrammar.getGlobalTypeDecl(decl.getName()) == null) {
          cachedGrammar.addGlobalTypeDecl(decl);
        }
      }

      /** Add new top-level attribute group definitions. **/
      map = newGrammar.getComponents(XSConstants.ATTRIBUTE_GROUP);
      length = map.getLength();
      for (int i = 0; i < length; ++i) {
        XSAttributeGroupDecl decl = (XSAttributeGroupDecl) map.item(i);
        if (cachedGrammar.getGlobalAttributeGroupDecl(decl.getName()) == null) {
          cachedGrammar.addGlobalAttributeGroupDecl(decl);
        }
      }

      /** Add new top-level model group definitions. **/
      map = newGrammar.getComponents(XSConstants.MODEL_GROUP);
      length = map.getLength();
      for (int i = 0; i < length; ++i) {
        XSGroupDecl decl = (XSGroupDecl) map.item(i);
        if (cachedGrammar.getGlobalGroupDecl(decl.getName()) == null) {
          cachedGrammar.addGlobalGroupDecl(decl);
        }
      }

      /** Add new top-level notation declarations. **/
      map = newGrammar.getComponents(XSConstants.NOTATION_DECLARATION);
      length = map.getLength();
      for (int i = 0; i < length; ++i) {
        XSNotationDecl decl = (XSNotationDecl) map.item(i);
        if (cachedGrammar.getGlobalNotationDecl(decl.getName()) == null) {
          cachedGrammar.addGlobalNotationDecl(decl);
        }
      }

      /**
       * Add all annotations. Since these components are not named it's
       * possible we'll add duplicate components. There isn't much we can
       * do. It's no worse than XMLSchemaLoader when used as an XSLoader.
       */
      XSObjectList annotations = newGrammar.getAnnotations();
      length = annotations.getLength();
      for (int i = 0; i < length; ++i) {
        cachedGrammar.addAnnotation((XSAnnotationImpl) annotations.item(i));
      }

    }

    public boolean containsGrammar(XMLGrammarDescription desc) {
      return false;
    }

    public Grammar getGrammar(XMLGrammarDescription desc) {
      return null;
    }

    public Grammar retrieveGrammar(XMLGrammarDescription desc) {
      return null;
    }

    public Grammar[] retrieveInitialGrammarSet(String grammarType) {
      return new Grammar[0];
    }
  }
}
